Brake for hoisting mechanism.



N0. 47,24l. Patented Apr. l0, I900.

r. J. SPRAGUE. BRAKE FOR HDISTING MECHANISM.

(Application filed Sept. 20, 1599;)

(No Model.)

Witnesses= Inventor Tra z'k J: Spr gua V 9 AL Z UJE'.

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UNITED STATES PATENT Quince.

FRANK J. SPRAGUE, OF NElV YORK, N. Y., ASSIGNOR TO THE SPRAGUE ELECTRIC COMPANY, OF NElV JERSEY.

BRAKE FOR HOISTING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 647,241, dated April 10, 1900.

Original application filed July 27, 1898, Serial No. 687,009. Divided and this application filed September 20,1899. Serial No.

T0 to whom it 771/001, concern.-

Be it known that I, FRANK J. SPRAGUE, a citizen of the United States of America, and a resident of the borough of Manhattan, in the city, county, and State of New York, have invented certain new and useful Improvements in Brakes for Hoisting Mechanism, (for which I have obtained a patent in Great Britain on an application filed December 31, 1897, No. 30,923, and sealed March 7, 1899, and a patent in France on an application filed March 3, 1898, and issued June 13,1898,No.275,549,) of which the following is a specification.

This application is filed as a division of application for Letters Patent of the United States filed July 27, 1898, Serial No. 687,009, for improvements in elevators.

These improvements relate particularly to an arrangement of brakes for ahoist-ing mechanism in which there are two driving-shafts, to which the brakes are simultaneously applied and released through suitable brake applying and releasing mechanism controlled from a single solenoid-magnet.

In the accompanying sheet of drawings, which forms a part of this specification, Figure 1 is an elevation of the end of a hoistingmachine with the brake mechanism arranged in accordance with my invention, the base of the machine and the frame with the solenoidmagnets being in section and the motors being removed. Fig. 2 is a side elevation of the hoisting-machine, showing one of the motors and the brake-wheeland brakes.

In its general features the hoisting mech anism consists of a Winding-drum 1, suitably mounted and driven through the agency of positive gearing, consisting of worm-gearing and spur-gearing, by two electric motors, the motor 2 being shown in Fig. 2. There are two driving mechanisms, one located at each side of the hoisting-machine, with the winding-drum between them. The driving-shafts 4 and 7 of both driving mechanisms and motors appear in section in Fig. 1, and one of the driving mechanisms is shown in Fig. 2 in dotted lines. 011 the shaft 4 is a left-hand worm 5, which engages the left-hand wormwheel 13, and on the shaft 7 is a right-hand worm 8, which engages the right-hand wormwheel 14. The two worm-wheels are mounted on a drum-shaft 10. A gear-shaft 11,with worm-wheels meshing with worms of opposite hands on the driving-shafts to the other worms on the driving-shafts, may be added to balance the end thrusts of the worms, as set forth in myoriginal patent application above named.

On each worm-shaft is a brake-wheel 20, and adjoining each brake-wheel is a pair of brake-levers 21, which carry suitable brakeshoes 22. The brake-levers are fulcrumed to standards 23, which are bolted to the bedplate of the machine. Near the opposite ends of each pair of levers are holes through which a brake-applyin g rod 24 is loosely passed. A head 25 at the lower end of the rod bears against the lower brake-lever, and a washer 26 bears against the upper brake-lever. The head of the rod and the washer are each so shaped in conjunction with the brake-lever against which it bears that each can rock slightly. tween the washer against the upper brake-lever and a washer which liesnnder nuts at the upper end of the brake-applying rod. The spring, which is compressed between the two washers, draws the ends of the. brake-levers together and applies the brake-shoes to the brake-wheel. Toggles 28 are attached to the ends of the brake-levers, and these when straightened separate the brake-levers and hold off the brake-shoes. The movement of the lower brake-lever is limited by the con tact of the head of the brake-applying rod with the bed-plate of the machine, and this movement is only half the spreading action of the toggles, so that the spreading action will also operate the upper brake-lever; but for this contact only the lower brake-lever would operate, since the weight of the upper brake-lever would keep its brake-shoe always in contact with the brake-wheel. The links of each set of toggles are connected to a softiron plunger 29, and the two plungers operate in opposite ends of the solenoid 30. This solenoid when energized attracts both plun- V gers and simultaneously releases the brakes A brake-applying spring 27 lies befrom both worm-shafts. When the circuit brake-levers to draw them together, toggles to separate the brake-levers, a solenoid, and I plungers operating in opposite ends of the I I solenoid and connected to the toggles, substantially as described.

this 13th day of July, 1899.

FRANK J. SPRAGUE. Witnesses:

SAMUEL W. BALcH, HUG-H PATTIsoN.

Signed by me in New York city, New York, 

